Motor vehicle crashes are the leading cause of injury death in America. The National Safety Council (NSC) estimates that several specific driver behaviors and errors contribute to 90 percent of all motor vehicle crashes. Crashes caused solely by vehicle or external factors (e.g., the failure of one or more vehicle components, the condition of the road, the weather, etc.) account for the other 10 percent of crashes.
At its most basic level, driving requires that a driver have the ability to adequately see, think, and react, and of course, these abilities change at different rates for different people as they get older. Not surprisingly, teenage drivers, who must learn new skills needed for driving and who frequently engage in high-risk behaviors, such as speeding and/or driving after using alcohol or drugs, have the highest fatality rate from motor vehicle crashes of all age groups, followed closely, based on miles driven, by older drivers (65 and older).
People 65 and older are the fastest-growing demographic in the United States, and by 2030, a quarter or all licensed drivers in the U.S. will be in that age group. Age alone, however, is not a reliable indicator of driving ability. Some people in their 90s and beyond, for example, are more healthy and fit for driving than many drivers half their age. Still, as a rule, it can be said that the older a person gets, the bigger risk he or she tends to pose as a driver. As the over-65 population grows, more elderly people will be driving more miles and more frequently, a fact which has led the National Highway Traffic Safety Administration (NHTSA) to predict that the number of elderly driver traffic fatalities in the U.S. could triple in number by 2030.
One phenomenon that afflicts young and old drivers alike is unintended acceleration, also known as “pedal error.” The consequences of pedal error can be devastating, as illustrated by two particularly distressing instances of this phenomenon that occurred fairly recently, each of which garnered national news coverage.
In 2001, a thirty-year-old driver backed her father's brand-new S.U.V. into a crowd outside a Southampton, N.Y., night club, injuring sixteen people. She got into the car, put it in reverse, and then twisted around to see if anyone was behind her, her foot slipping off the pedal as she did so. As a result, the trajectory of her right foot was thrown off by a few inches, and when she put her foot back down, what she thought was the brake was actually the accelerator. The car leapt backwards. She panicked. She pressed harder on the accelerator, trying to stop the car. But her action made the car speed up. The driver was parked approximately fifty feet from the night club, and assuming that she was accelerating at a rate of 0.4 g's (not unlikely, given the 342-horsepower vehicle she was driving), she would have covered that fifty feet in roughly 2.8 seconds. Wade Bartlett, an expert in mechanical forensics who has studied more than three dozen cases of unintended acceleration, has said, “When faced with a completely new situation, it would not be unusual for someone to require three seconds to figure out what's going on and what to do about it.” In some instances, it has been reported that drivers have mistakenly continued to press the accelerator for up to thirty seconds.
In 2003, an 86-year-old man plowed through a crowded farmers' market on a street closed to traffic in Santa Monica, Calif., striking scores of pedestrians and vendor displays in the process. His car proceeded through the farmers' market for approximately 2 blocks (750 feet), traveling as fast as 70 mph before coming to rest after hitting a ditch. As a result of the accident, 10 people were killed and 63 injured, many grievously so.
In the National Transportation Safety Board (NTSB) investigation which followed the 2003 incident in Santa Monica, the NTSB ruled out many potential causes of accident: weather; driver's experience and familiarity with his vehicle and area; alcohol; illicit medications; insufficient sleep or fatigue. The report instead concluded that the driver had inadvertently accelerated when he intended to brake, a textbook case of pedal error. The report went on to note that the driver most likely reverted to a habitual response of hard braking, or “pumping,” the brakes as his stress level increased and the vehicle failed to slow. However, because his foot was on the accelerator instead of the brake pedal, this response led to increased acceleration. The ineffectiveness of the driver's efforts to stop his vehicle and the realization that he was striking objects in his path, very likely increased the already high level of stress affecting him, thereby impeding his ability to quickly detect and correct his earlier error in response execution.
The unintended acceleration that results from pedal error almost invariably causes the afflicted driver to go into a hypervigilant or panicked state. When a driver enters a hypervigilant state, he or she becomes desensitized to stimulation from peripheral vision and begins to experience such feelings as helplessness, simplistic ‘childlike’ thinking, distractibility, and not considering the consequences of one's errors as signs of the stresses. A driver in a hypervigilant state would be looking straight ahead (or behind) at all the things he or she was approaching, riveted by those things and terrified that he or she was about to hit them, but would be unable to steer away from them.
At least four factors have been associated with an increased probability of unintentional acceleration caused by pedal error. It happens more frequently to both older and younger drivers, to people who are unfamiliar with the cars they are driving, and to people who have just gotten into a car and started it up.
Another driver behavior that presents obvious dangers is the intentional acceleration of a motor vehicle, as in unauthorized drag racing. Not surprisingly, most incidents involving intentional acceleration involve teenage drivers.
Based on the foregoing, an urgent need exists for systems and methods directed to preventing not only the unintentional acceleration that results from pedal error but also the most extreme forms of intentional acceleration. While reading the following summary of the invention, the reader should keep in mind that left-foot braking was pioneered in the sixties and has been practiced for decades by race car drivers.